Forging device and re-centering attachment of forging device

ABSTRACT

Disclosed is a forging device containing a die insert 1, a stationary die case 2, a movable part (Ram) 3, a punch holder 4, and a punch tool 5. The punch holder 4 contains upper and lower reference stud holes 14,15, upper and lower reference studs 7,8 loosely fitted in the respective holes 14,15 in the movable part 3, an alignment adjusting bolt 17T, etc. to be tightened into a direction of the stud 7 to move the punch holder 4 in an alignment direction, and clamping nuts 9 engaged with the respective studs 7,8, to fix the punch holder 4. A positioning nut 22T is received by a male screw portion 21 of at least one alignment transcription bolt 20T and fixed thereto, and the nut 22 is brought into contact with the punch holder 4 at a complete alignment position, whereby the bolt 20T and the punch tool 5 should be attached/detached as a pair.

TECHNICAL FIELD

The present application relates to a forging device (punch holder) that forges a metal material in a die by forcing pressure by punch and to an alignment transcription attachment coupled to a forging device.

BACKGROUND ART

Conventionally, a slide-type horizontal forging device, such as a continuous multi-station parts former or header is used as a device for forging metal parts from wire or bar materials by deformation processing under high speed production.

Patent Literature 1 in the Citation List discloses a continuous multi-station parts former in which forging devices performing five forming steps are disposed in a lateral row.

As illustrated in FIG. 7, the forging device of Patent Literature 1 contains a stationary die case 102 with a die insert 101, a movable part (RAM) 103 horizontally and reciprocally movable to and away from the stationary die case 102, a punch holder 104 detachably bolted to the movable part 103, and a punch tool 105 that is paired with the die insert 101 and is detachably clamped to the punch holder 104.

The punch holder 104 contains an upper clamp stud hole 106 drilled through the punch holder 104 with the axis of the upper clamp stud hole 106 along the moving direction of the movable part 103 in the lateral direction; a lower clamp stud hole 107 drilled through the punch holder 104 with the axis of the lower clamp stud hole 107 along the moving direction of the movable part 103 in an opposing side of the upper clamp stud hole 106 directly below the upper clamp stud hole 106 across the punch tool 105; a upper clamp stud 108 fixed on the movable part 103 such that the upper clamp stud 108 is loosely fitted in the upper clamp stud hole 106 of the punch holder 104; a lower clamp stud 109 attached to the movable part 103 such that the lower clamp stud 109 is vertically free fitted in the lower clamp stud hole 107 of the punch holder 104; a plurality of alignment adjusting bolts 110 that sit against the upper clamp stud 108 and are fastened from outside the punch holder 104 into a direction of the upper clamp stud 108 to move the punch holder 104 for aligning the punch tool 105 with fixing the punch holder 104 at a position of the lower clamp stud 109; and clamping nuts 111,111 which are engaged with the upper clamp stud 108 and the lower clamp stud 109, respectively, and consequently they keep and hold the punch holder 104 at a complete alignment position.

In FIG. 7, numeral number 112 denotes a moving Ram, numeral number 113 denotes a front/back adjusting wedge, and numeral number 114 denotes a punch holder mounting plate. The moving Ram 112, the front/back adjusting wedge 113, and the punch holder mounting plate 114 constitute the movable part 103. The mounting plate 114 is stacked on the adjusting wedge 113 on the side facing the stationary die case 102, and supports the upper and lower clamp studs 108,109.

The forging device can produce various type of parts by exchanging the die insert 101 and the punch tool 105. However, in each changeover, an operator needs to check so-called alignment of the punch tool 105 and the die insert 101 in the stationary die case 102 and needs to move the punch holder 104 to get the alignment against die insert 101 for respective jobs.

Generally, the radial clearance between the die insert 101 and the punch tool 105 is in a range of 8/100 to 5/100 mm. The tolerance for misalignment between the die insert 101 and the punch tool 105 is 3/100 mm or less, at the largest, when an off-center load is applied to the movable part 103. If the misalignment exceeds the range, the punch tool 105 or the die insert 101 would face the risk of being broken.

Accordingly, based on operator's experiences and in view of the shape of a forged test piece, an operator needs to perform fine adjustment carefully over time to make sure that the misalignment falls within the allowable range. It takes a long time even for an aged expert.

Especially, in a continuous multi-station parts former, multiple steps including blank cutoff, upsetting, and piercing are performed simultaneously with multiple die inserts 101 and punch tools 105 disposed in a lateral row during one reciprocal movement of the movable part 103. An off-center forming load is applied to a workpiece in each step since deformation ratio of the workpiece varies in each step. As a result, an off-center load is applied to the movable part 103 as a whole. Accordingly, the operator needs to perform fine adjustment for every station of punch tool 105 in the movable part 103 and it is troublesome for the operators.

The inefficiency in alignment adjusting operation has become a great issue of production efficiency since continuous multi-station parts formers with nine or ten stations are developed recently in response to demands for net-shaped parts production in the cold forging field.

To overcome the inefficiency in the alignment adjusting operation, the continuous multi-station parts former of Patent Literature 1 incorporates, as illustrated in an exploded perspective view in FIG. 8, a cylindrical sleeve 118 mounted on the alignment adjusting bolt 110 to be slidable in the axial direction and be rotatable with the alignment adjusting bolt 110 by loose fit of an inward key 117 of the sleeve 118 onto a key groove 116 linearly incised on a male screw portion 115 of the alignment adjusting bolt 110; a dial plate 119 loosely and adjustably mounted on the sleeve 118; and a setscrew 120 tightened from an outside of the dial plate 119 to couple the sleeve 118 and the dial plate 119. The scale of the dial plate 119 shows the state of the alignment adjusting bolt 110 in scale after the alignment operation was done.

CITATION LIST Patent Literature

Patent Literature 1: JPY63-20434

SUMMARY OF INVENTION Technical Problem

The configuration of Patent Literature 1 that contains the alignment adjusting bolt 110, the sleeve 118, the dial plate 119, and the setscrew 120 has the following problems.

First, the alignment adjusting bolt 110 and the sleeve 118 are co-rotatable by engagement between the key 117 and the key groove 116. To ensure slidability, a predetermined clearance is made between the key 117 of the sleeve 118 and the key way 116 of the alignment adjusting bolt 110. However, the clearance sacrifices accuracy of co-rotational movement of the alignment adjusting bolt 110 and the sleeve 118. Further, when setting the scale of the dial plate 119 by visual confirmation, an error may occur depending on the degrees of skill of the operators or on viewing angles of the dial plate 119 by the operators, leading to further degradation in accuracy. In the current technology, the accuracy of 1/100 to 4/100 mm is required but it is very difficult to attain such accuracy.

Second, although the dial plate 119 is fixed onto the sleeve 118, the sleeve 118 slides on the alignment adjusting bolt 110 along with the dial plate 119. Accordingly, once the alignment adjusting bolt 110 is loosened by rotations, it will be difficult to reproduce the state of the alignment adjusting bolt 110 without recording the number of the rotation of the bolt 110. Especially, in case where the both left and right alignment adjusting bolts 110, 110 are loosened, it will hardly be possible to reproduce the state of the alignment adjusting bolts 110, 110 since no basic reference of the alignment cannot be retained.

The present application was made to overcome the problems, and to provide a forging device (machine) and an alignment transcription attachment for a forging device configured to effectively conduct a re-alignment operation when an aligned punch is removed from a punch holder and is re-mounted onto the punch holder.

Solution to Problem

The present application provides a forging device (machine) containing:

a stationary part containing a die,

a movable part reciprocally movable to and away from the stationary part in a moving direction,

a punch holder detachably attached to the movable part, and

a punch tool that is paired with the die and is detachably attached to the punch holder,

the punch holder containing:

an upper reference stud hole drilled through the punch holder with an axis of the upper reference stud hole along the moving direction of the movable part,

a lower reference stud hole drilled through the punch holder with an axis of the lower reference stud hole along the moving direction of the movable part in an opposing side of the upper reference stud hole across the punch tool,

an upper reference stud fixed to the movable part such that the upper reference stud is loosely fitted in the upper reference stud hole of the punch holder,

a lower reference stud fixed to the movable part such that the lower reference stud is loosely fitted in the lower reference stud hole of the punch holder, wherein either the upper reference stud or each of the upper and lower reference studs is defined as a reference stud, and either the upper reference stud hole or the lower reference stud hole in which the reference stud is loosely fitted is defined as a reference stud hole,

a plurality of adjusting bolts each comprising a male screw portion, the adjusting bolts to be tightened with respect to the reference stud from an outer side of the punch holder into a direction of the reference stud to move the punch holder into an alignment direction, defined as a direction in which the punch holder is moved to align the punch tool and the die, with fixing the punch holder at a position of the reference stud,

clamping nuts which are engaged with the upper reference stud and the lower reference stud, respectively, and fix the punch holder at a complete alignment position, defined as a position at which the punch tool and the die are aligned, and

a positioning nut which is received by at least one of the adjusting bolts in movable engagement therewith,

wherein the positioning nut can be non-rotatably fixed to the male screw portion of the adjusting bolts with the positioning nut put in contact with an outer surface of the punch holder set at the complete alignment position, whereby the positioning nut is fixed on the adjusting bolt in association with the complete alignment position,

wherein the adjusting bolt on which the positioning nut is fixed and the punch tool in the punch holder are attached to and detached from the punch holder in pairs.

It is preferred that the adjusting bolts contain a first group of adjusting bolts used for a normal alignment adjusting operation, defined as an operation in which information on a formerly performed alignment adjusting operation is not used, and a second group of adjusting bolts used for an alignment transcription operation, defined as an operation in which the punch tool and the die are aligned at the same position with a formerly aligned position, wherein the first group of adjusting bolts and the second group of adjusting bolts are displaced from one another and the second group of adjusting bolts receive the positioning nuts.

It is preferred that the adjusting bolt receiving the positioning nut is a headless screw with a recess at an axial end thereof for engagement with a fastening tool.

It is preferred that the forging device contains an alignment transcription attachment containing:

a thick-plate shaped block body that is set in contact with a surface of the punch holder on a side facing the stationary part,

an extended bolt hole drilled in the block body to communicate with the reference stud hole, and

the adjusting bolts used in an alignment transcription operation and to be tightened from an outer side of the punch holder into a direction of the reference stud, wherein the alignment transcription operation is defined as an operation in which the punch tool and the die are aligned at the same position with a formerly aligned position, and the alignment transcription attachment is coupled to the punch holder with the extended bolt hole communicating with the reference stud hole.

The present application provides an alignment transcription attachment to be coupled to a forging device, the forging device containing:

a stationary part containing a die,

a movable part reciprocally movable to and away from the stationary part in a moving direction,

a punch holder detachably attached to the movable part, and

a punch tool that is paired with the die and is detachably attached to the punch holder;

the punch holder containing:

an upper reference stud hole drilled through the punch holder with an axis of the upper reference stud hole along the moving direction of the movable part,

a lower reference stud hole drilled through the punch holder with an axis of the lower reference stud hole along the moving direction of the movable part in an opposing side of the upper reference stud hole across the punch tool,

an upper reference stud fixed to the movable part such that the upper reference stud is loosely fitted in the upper reference stud hole of the punch holder,

a lower reference stud fixed to the movable part such that the lower reference stud is loosely fitted in the lower reference stud hole of the punch holder, wherein either the upper reference stud or each of the upper and lower reference studs is defined as a reference stud, and either the upper reference stud hole or the lower reference stud hole in which the reference stud is loosely fitted is defined as a reference stud hole,

a plurality of adjusting bolts each containing a male screw portion, the adjusting bolts to be tightened with respect to the reference stud from an outer side of the punch holder into a direction of the reference stud to move the punch holder into an alignment direction, defined as a direction in which the punch holder is moved to align the punch tool and the die, with fixing the punch holder at a position of the reference stud, and

clamping nuts which are engaged with the upper reference stud and the lower reference stud, respectively, and fix the punch holder at the complete alignment position, defined as a position at which the punch tool and the die are aligned,

the alignment transcription attachment containing:

a substantially thick-plate shaped block body that is set in contact with a surface of the punch holder at a portion covering the upper reference stud hole on a side facing the stationary part,

an extended bolt hole drilled through the block body to communicate with the reference stud hole of the punch holder,

an adjusting bolt tightened into a direction of the extended bolt hole from the outer side of the punch holder to be in contact with the reference stud, and

a positioning nut movably engaged with the male screw portion of the adjusting bolt, wherein

the block body is coupled or bolted to the punch holder with the extended bolt hole communicating with the reference stud hole, the adjusting bolt of the block body is tightened till the bolt hits the reference stud in alignment, the positioning nut is tightened till the positioning nut hits the block body, and the tightened positioning nut is un-rotatably fixed to the male screw portion of the adjusting bolt.

Advantageous Effects of Invention

In the forging device described above, the positioning nut, when it is un-rotatably fixed onto the male screw portion of the adjusting bolt, physically stores therein information on an alignment of the aligned punch tool. Accordingly, if the adjusting bolt and the punch tool are detached from and mounted onto the punch holder as a pair, then an alignment transcription operation of the punch may be effectively performed.

The adjusting bolts contains a first group of bolts used for a normal alignment adjusting operation, defined as an operation in which information on a formerly performed alignment adjusting operation is not used, and a second group of bolts used for alignment transcription operation, defined as an operation in which the punch tool and the die are aligned at the same position as a formerly aligned position, wherein the first group of adjusting bolts and the second group of adjusting bolts are displaced from one another and the second group of adjusting bolts receive the positioning nuts. Accordingly, the adjusting bolts used for a normal alignment adjusting operation and the adjusting bolts used for an alignment transcription operation are mounted separately, whereby accuracy in alignment transcription will last for a long period. Usually, the adjusting bolts are repeatedly tightened or loosened for the normal alignment adjusting operations. As a result, contact points of the reference stud and the top of the adjusting bolts are prone to be de formed by usual alignment adjusting operations. Meanwhile, the adjusting bolts used for an alignment transcription operation hardly cause wearing of the reference stud since it is enough in an alignment transcription operation that the adjusting bolts are tightened with a predetermined torque until the positioning nuts are in solid contact with the punch holder.

Further, when multiple forging devices are disposed in a lateral row such as in a continuous multi-station parts former (type of forging machine), enough room may not be secured for attaching/detaching the adjusting bolts due to interference of the adjacent bolts. Where the adjusting bolts used for a normal alignment adjusting operation and the adjusting bolts used for an alignment transcription operation are displaced from one another, a space is easily secured for attaching/detaching the adjusting bolts used for an alignment transcription operation.

The adjusting bolt receiving the positioning nut is a headless screw with a recess at an axial end thereof for engagement with a fastening tool.

Where the alignment transcription screws receiving the positioning nuts are each headless screws with a recess at an axial end thereof for engagement with a fastening tool, a space is easily secured for attaching/detaching the adjusting bolt used for an alignment transcription operation since the adjusting bolts are shorten by size of a bolt head portion. Herein, the headless screw includes screws with a recess, which is formed for engagement with a fastening tool, in the form of a socket head set screw, a slotted end screw, fillips end screw, or a specific shape screw with hole like torx set screw for engagement with a specific fastening tool.

The forging device contains a alignment transcription attachment containing a thick-plate shaped block body that is set in contact with a surface of the punch holder on a side facing the stationary part, an extended bolt hole drilled in the block body to communicate with the reference stud hole, and the adjusting bolts used in an alignment transcription operation and to be tightened from an outer side of the punch holder into a direction of the reference stud, wherein the alignment transcription operation is defined as an operation in which the punch tool and the die are aligned at the same position with a formerly aligned position, and the alignment transcription attachment is coupled to the punch holder with the extended bolt hole communicating with the reference stud hole.

The present application provides an alignment transcription attachment to be coupled to a forging device, the forging device containing:

a stationary part containing a die,

a movable part reciprocally movable to and away from the stationary part in a moving direction,

a punch holder detachably attached to the movable part, and

a punch that is paired with the die and is detachably attached to the punch holder;

the punch holder containing:

an upper reference stud hole drilled through the punch holder with an axis of the upper reference stud hole along the moving direction of the movable part,

a lower reference stud hole drilled through the punch holder with an axis of the lower reference stud hole along the moving direction of the movable part in an opposing side of the upper reference stud hole across the punch tool,

an upper reference stud fixed to the movable part such that the upper reference stud is loosely fitted in the upper reference stud hole of the punch holder,

a lower reference stud fixed to the movable part such that the lower reference stud is loosely fitted in the lower reference stud hole of the punch holder, wherein either the upper reference stud or each of the upper and lower reference studs is defined as a reference stud, and either the upper reference stud hole or the lower reference stud hole in which the reference stud is loosely fitted is defined as a reference stud hole,

a plurality of adjusting bolts each containing a male screw portion, the adjusting bolts to be tightened with respect to the reference stud from an outer side of the punch holder into a direction of the reference stud to move the punch holder into an alignment direction, defined as a direction in which the punch holder is moved to align the punch tool and the die, with fixing the punch holder at a position of the reference stud, and

clamping nuts which are engaged with the upper reference stud and the lower reference stud, respectively, and fix the punch holder at a complete alignment position, defined as a position at which the punch tool and the die are aligned,

the alignment transcription attachment containing:

a substantially thick-plate shaped block body that is set in contact with a surface of the punch holder at a portion covering the upper reference stud hole on a side facing the stationary part,

an extended bolt hole drilled through the block body to communicate with the reference stud hole of the punch holder,

an adjusting bolt tightened into a direction of the extended bolt hole from the outer side of the punch holder to be in contact with the reference stud, and

a positioning nut movably engaged with the male screw portion of the adjusting bolt, wherein

-   -   the block body is coupled or bolted to the punch holder with the         extended bolt hole communicating with the reference stud hole,         the adjusting bolt of the block body is tightened till the bolt         hits the reference stud in alignment, the positioning nut is         tightened till the positioning nut hits the block body, and the         tightened positioning nut is un-rotatably fixed to the male         screw portion of the adjusting bolt. Accordingly, where the         alignment transcription attachment is configured to be coupled         to the punch holder, it is easy to fit the alignment         transcription attachment to a conventional forging device         (machine).

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view of a punch holder.

FIG. 2 is a front view of the forging device viewed from the side of a movable part.

FIG. 3 is a cross-sectional view along line A-A of FIG. 2.

FIG. 4 is a main part enlarged front view of a punch holder partly shown in cross-section.

FIG. 5 is an exploded perspective view of an alignment transcription attachment.

FIG. 6 is an exploded perspective view of a punch holder according to another example.

FIG. 7 is a longitudinal cross-sectional view of a conventional forging device.

FIG. 8 is an exploded perspective view of a conventional alignment adjusting bolt.

DESCRIPTION OF EMBODIMENTS

Hereinafter, specific descriptions of a preferred embodiment of the present application will be provided with reference to the drawings.

The forging device (machine) contains a stationary die case (die block) 2 containing a die insert 1, a movable part (Ram) 3 horizontally slide to and away from the stationary die case 2, a punch holder 4 detachably attached to the movable part (Ram) 3, and a punch tool 5 that is paired with the die insert 1 and is detachably attached to the punch holder 4.

The stationary die case 2 contains the die insert 1 detachably. The stationary die case 2 and the die insert 1 are the same as the ones adopted in the conventional forging device (machine), and therefore the detailed description thereof is omitted herein.

Although not illustrated in Figures, the movable part (Ram) 3 contains the moving ram 112 and the adjusting wedge 113 described for the background art. A mounting plate 6 is fixedly mounted on the adjusting wedge 113 on the side facing the stationary die case 2. The moving ram 112, the adjusting wedge 113, and the mounting plate 6 of the movable part 3 horizontally slides in a lateral direction to and away from the stationary die case 2 by means of a driving unit not illustrated in Figures. The moving ram 112, the adjusting wedge 113, and the driving unit are the same as the ones adopted in the conventional forging device(machine), and therefore the detailed description thereof is omitted herein.

An upper reference stud 7 is mounted on the mounting plate 6 of the movable part (Ram) 3 with the axis of the upper stud 7 along the reciprocal moving direction of the movable part (Ram) 3, and a similar lower reference stud 8 is mounted on the mounting plate 6 at a vertically downward position with respect to the upper reference stud 7. The upper reference stud 7 and the lower reference stud 8 engage with paired clamping nuts 9, 9 along with washers 10, 10, respectively. The upper and lower reference studs 7, 8 each may have a composite structure with a sleeve on its outer peripheral, although the studs 7, 8 are illustrated in Figures as the ones having a simple structure without a sleeve.

As illustrated in FIG. 1, the punch holder 4 contains a cylindrical main holder 11 setting the punch tool 5, a thick plate-like first mounting piece 12 that has a square shape and extends upward from the base part of the main holder 11, and a thick plate-like second mounting piece 13 that has a square shape and extends downward from the base part of the main holder 11.

An upper reference stud hole 14, which is larger than the upper reference stud 7 in diameter, is drilled in the first mounting piece 12 of the punch holder 4 with the axis of the stud hole 14 along the moving direction of the movable part 3. A vertically long lower reference stud hole 15, which is the same in width with and longer in length than the lower reference stud 8, is drilled in the second mounting piece 13 with the axis of the stud hole 15 along the moving direction of the movable part 3. The upper reference stud 7 loosely fits in the upper reference stud hole 14 with the stud 7 relatively movable in all directions within the hole 14, while the lower reference stud 8 loosely fits in the lower reference stud hole 15 with the stud 8 relatively movable in the vertical direction within the hole 15.

Screw holes 16T, 16L, and 16R are furnished behind the first mounting piece 12 of the punch holder 4 from outer sides of top end surface, left-side end surface, and right-side end surface of the first mounting piece 12 toward the center of the upper reference stud hole 14. Three alignment adjusting bolts 17T, 17L and 17R are engaged with the screw holes 16T, 16L, and 16R, respectively.

In FIG. 2, when the adjusting bolt 17T is tightened, the punch holder 4 moves in an upward direction with the punch holder 4 fixed at the position of the upper reference stud 7. When the left-side adjusting bolt 17L is tightened, the punch holder 4 tilts in a leftward direction around the lower reference stud 8 as a pivot with the punch holder 4 fixed at the position of the upper stud 7. When the right-side adjusting bolt 17R is tightened, the punch holder 4 tilts in a rightward direction around the lower reference stud 8 as a pivot with the punch holder 4 fixed at the position of the upper stud 7. Such movement of the punch holder 4 allows the punch tool 5 held in the main holder 11 to move in the vertical and horizontal directions, so that the alignment of the punch tool 5 can be adjusted to align with the stationary die 1.

Although the above-described forging device is a traditionally well-known device, an embodiment of the present application is characterized in that an alignment transcription attachment 18 illustrated in FIG. 5 is fixed to the first mounting piece 12 of the punch holder 4.

The alignment transcription attachment 18 contains, as a main body, a substantially thick plate-like metal block body 12 x that is shaped to fit with the first mounting piece 12 of the punch holder 4. The alignment transcription attachment 18 further contains an extended bolt hole 14 x drilled through the block body 12 x to communicate with the upper reference stud hole 14 of the first mounting piece 12; a tapped hole 191 machined from the top end surface of the block body 12 x toward the center of the extended bolt hole 14 x; a tapped hole 19L machined from the left end surface of the block body 12 x toward the center of the extended bolt hole 14 x when viewed in FIG. 2; a tapped hole 19R machined from the right end surface of the block body 12 x toward the center of the extended bolt (stud) hole 14 x when viewed in FIG. 2; alignment transcription bolts(hexagon socket set screw) 20T, 20L, and 20R engaged with the tapped holes 19T, 19L, and 19R, respectively; and positioning nuts 22T, 22L, and 22R movably engaged with male screw portions 21 of the alignment transcription bolts 20T, 20L, and 20R, respectively.

Each of the alignment transcription bolts 20T, 20L, and 20R of the alignment transcription attachment 18 has no bolt head like a hexagon head bolt and is a headless screw with a recess 23 that is formed for engagement with a fastening tool in the form of a hexagonal hole, a negative setscrew, or a phillip setscrew, for example.

The alignment transcription attachment 18 is fixed (bolted) to and integrated with the first mounting piece 12 of the punch holder 4 on the side thereof facing the stationary die case 2 by connection means such as brazing and welding with the extended bolt hole 14 x communicating with the upper reference stud hole 14. Consequently, the fixed alignment transcription attachment 18 constitutes a part of the punch holder 4 and the extended bolt hole 14 x constitutes a part of the upper reference stud hole 14. Accordingly, hereunder, the upper reference stud hole 14 is deemed to contain the extended bolt hole 14 x, unless otherwise expressed.

As illustrated in FIG. 2, the present embodiment employs a continuous multi-station parts former (machine) in which multiple forging devices (punch holders) are disposed in a lateral row. The movable part 3 is provided with multiple punch holders 4 and the stationary die case 2 holds multiple die inserts 1.

To perform an alignment adjusting operation in the forging device according to the present embodiment, first, all adjusting bolts 17T, 17L, and 17R, and alignment transcription bolts 20T, 20L, and 20R are kept away from the upper reference stud hole 14, and the punch tool 5 is mounted into the punch holder 4 with mounting the clamping nuts 9, 9 on the respective upper and lower reference studs 7, 8 loosely.

Then, the alignment adjusting bolts 17T, 17L, and 17R in the first mounting piece 12 is adjusted through tightening as described above for moving the punch holder 4 to align the punch tool 5 with the die insert 1.

With the alignment kept, the clamping nuts 9, 9 of the respective upper and lower reference studs 7 and 8 are tightened to fix the punch holder 4. The position of the punch holder 4 in this moment at which the punch holder 4 fixed with the alignment kept is defined as a complete alignment position.

Then, the alignment transcription bolts 20T, 20L, and 20R of the alignment transcription attachment 18 are tightened with a predetermined tightening torque using a tightening tool till they hit against the upper reference stud 7 being tightened with the nuts 9,9 in relation with the complete alignment position. Then, the positioning nuts 22T, 22L, and 22R engaged with the respective male screw portions 21 of the alignment transcription bolts 20T, 20L, and 20R are tightened with a predetermined tightening torque till they hit against the block body 12 x. Then, the tightened positioning nuts 22T, 22L, and 22R are un-rotatably fixed over the respective male screw portions 21 using fixing methods such as adhesive locking agent or caulking tools.

By following the above described steps, the alignment transcription operation is completed. Then, forging is performed with the aligned punch tool 5. When the forging is completed and the punch tool 5 is removed from the punch holder 4 for exchange, another punch tool is set into the punch holder 4 in the aforementioned manner. Concurrently with exchange of the punch tool 5, the alignment transcription bolts 20T, 20L, and 20R of the alignment transcription attachment 18 are removed and exchanged to other ones.

The removed punch tool 5, and the alignment transcription bolts 20T, 20L, and 20R, on which the respective positioning nuts 22T, 22L, and 22R are fixed, are stocked in pairs. It is preferred that identification means are applied to the paired punch tool 5 and the alignment transcription bolts 20T, 20L, and 20R to accomplish correct re-engagement of the alignment transcription bolts 20T, 20L, and 20R with the corresponding tapped holes 19T, 19L, and 19R by coloring or marking the positioning nuts 22T, 22L, and 22R, or the alignment transcription bolts 20T, 20L, and 20R, for example, to distinguish the alignment transcription bolt 20T as the top-side bolt, the alignment transcription bolt 20L as the left-side bolt, and the alignment transcription bolt 20R as the right-side bolt, for example.

Remounting the removed punch tool 5 into the punch holder 4 is performed such that the punch tool 5 is mounted into the punch holder 4; the alignment transcription bolts 20T, 20L, and 20R stocked with the punch tool 5 are re-engaged with the screw holes 19T, 19L, and 19R of the alignment transcription attachment 18, respectively; and the positioning nuts 22T, 22L, and 22R fixed on the respective male screw portions 21 are tightened with a predetermined torque till they hit against the block body 12 x. During remounting, the alignment adjusting bolts 17T, 17L, and 17R used in a normal alignment adjusting operation are loosened enough to be kept away from the upper reference stud hole 14. Consequently, the alignment transcription bolts 20T, 20L, and 20R hit against the upper reference stud 7, and the complete alignment position of the punch holder 4 is correctly reproduced with the upper reference stud 7 fixed with three contact points. Under the conditions, the clamping nuts 9, 9 for the respective upper and lower reference studs 7 and 8 are tightened. Thus, an alignment transcription operation is completed quickly, in very short time.

A preferred embodiment of the present application has been described above. However, the embodiment of the present application is not limited thereto. In the preferred embodiment, the alignment transcription attachment 18 is configured to contain the alignment transcription bolts 20T, 20L, and 20R used for an alignment transcription operation and to be coupled to the punch holder 4. However, the punch holder 4 may be integrally casted, machined or formed to contain a bulged part that is equivalent to the alignment transcription attachment 18 in shape and structure.

Further, in the preferred embodiment, three alignment transcription bolts 20T, 20L, and 20R are used for an alignment transcription operation. However, even if only one of the alignment transcription bolts 20T, 20L, and 20R is used, efficiency of alignment adjusting operation is improved. In case where only the left side alignment transcription bolt 20L in FIG. 2 of the preferred embodiment is used, if the alignment transcription bolt 20L is tightened and then the right-side alignment adjusting bolt 17R used for a normal alignment adjusting operation is tightened, then alignment of the punch holder 4 in lateral position is reproduced, since the alignment transcription bolt 20L serves a reference point. In this case, it takes a conventional level of time for adjusting the punch holder 4 in vertical direction since the alignment adjusting bolt 17T for a normal alignment adjusting operation is used. However, efficiency in alignment adjusting will be improved in total. The same is true of the case where only the top-side alignment transcription bolt 20T or the right-side alignment transcription bolt 20R is used. Alternatively, two alignment transcription bolts of the top-side alignment transcription bolt 20T and either one of the lateral alignment transcription bolts 20L, 20R may be adapted for alignment transcription operation. In multiple forging devices furnished in a lateral row, it is advantageous to use either one of the alignment transcription bolts 20L and 20R since a space for attachment/detachment of the alignment transcription bolt 20L or 20R is surely secured and work efficiency is improved.

In the preferred embodiment, the alignment adjusting bolts 17T, 17L, and 17R used for a normal alignment adjusting operation are provided separately from the alignment transcription bolts 20T, 20L, and 20R used for an alignment transcription operation. However, the alignment transcription bolts 20T, 20L, and 20R combined with the respective positioning nuts 22T, 22L, and 22R in one piece can be used for a normal alignment adjusting operation instead of the alignment adjusting bolts 17T, 17L, and 17R. In this case, a drawback occurs such that the contact points of upper reference stud 7 in contact with the alignment transcription bolts 20T, 20L, and 20R may be partly getting worn and damaged, leading to gradual deterioration in accuracy. However, as far as deformation of the upper reference stud 7 due to wearing falls within a limited range, work efficiency is still improved.

In the preferred embodiment, the alignment transcription bolts 20T, 20L, and 20R are used only for the upper reference stud 7. However, in case where the lower reference stud hole 15 is worn and the space between the wall of the lower reference stud hole and the lower reference stud is expanded or worn out due to long term use, alignment transcription bolts 20T, 20L, 20R, etc. could be used also for the lower reference stud 8, as illustrated in FIG. 6. 

1. A forging device comprising: a stationary part comprising a die, a movable part reciprocally movable to and away from the stationary part in a moving direction, a punch holder detachably attached to the movable part, and a punch tool that is paired with the die and is detachably attached to the punch holder; the punch holder comprising: an upper reference stud hole drilled through the punch holder with an axis of the upper reference stud hole along the moving direction of the movable part, a lower reference stud hole drilled through the punch holder with an axis of the lower reference stud hole along the moving direction of the movable part in an opposing side of the upper reference stud hole across the punch tool, an upper reference stud fixed to the movable part such that the upper reference stud is loosely fitted in the upper reference stud hole of the punch holder, a lower reference stud fixed to the movable part such that the lower reference stud is loosely fitted in the lower reference stud hole of the punch holder, wherein either the upper reference stud or each of the upper and lower reference studs is defined as a reference stud, and either the upper reference stud hole or the lower reference stud hole in which the reference stud is loosely fitted is defined as a reference stud hole, a plurality of adjusting bolts each comprising a male screw portion, the adjusting bolts to be tightened with respect to the reference stud from an outer side of the punch holder into a direction of the reference stud to move the punch holder into an alignment direction, defined as a direction in which the punch holder is moved to align the punch tool and the die, with fixing the punch holder at a position of the reference stud, clamping nuts which are engaged with the upper reference stud and the lower reference stud, respectively, and fix the punch holder at a complete alignment position, defined as a position at which the punch tool and the die are aligned, and a positioning nut which is received by at least one of the adjusting bolts in movable engagement therewith, wherein the positioning nut can be non-rotatably fixed to the male screw portion of the adjusting bolts with the positioning nut put in contact with an outer surface of the punch holder set at the complete alignment position, whereby the positioning nut is fixed on the adjusting bolt in association with the complete alignment position, wherein the adjusting bolt on which the positioning nut is fixed and the punch tool in the punch holder are attached to and detached from the punch holder in pairs.
 2. The forging device according to claim 1, wherein the adjusting bolts comprise: a first group of adjusting bolts used for a normal alignment adjusting operation, defined as an operation in which information on a formerly performed alignment adjusting operation is not used, and; a second group of adjusting bolts used for an alignment transcription operation, defined as an operation in which the punch tool and the die are aligned at the same position with a formerly aligned position, wherein the first group of adjusting bolts and the second group of adjusting bolts are displaced from one another and the second group of adjusting bolts receive the positioning nuts.
 3. The forging device according to claim 1, wherein the adjusting bolt receiving the positioning nut is a headless screw with a recess at an axial end thereof for engagement with a fastening tool.
 4. The forging device according to claim 1 comprises an alignment transcription attachment comprising: a thick-plate shaped block body that is set in contact with a surface of the punch holder on a side facing the stationary part, an extended bolt hole drilled in the block body to communicate with the reference stud hole, and the adjusting bolts used in a alignment transcription operation and to be tightened from an outer side of the punch holder into a direction of the reference stud, wherein the alignment transcription operation is defined as an operation in which the punch tool and the die are aligned at the same position with a formerly aligned position, and the alignment transcription attachment is coupled to the punch holder with the extended bolt hole communicating with the reference stud hole.
 5. The forging device according to claim 2, wherein the second group of adjusting bolts receiving the positioning nuts are each headless screw like hexagon socket set screw with a recess at an axial end thereof for engagement with a fastening tool.
 6. The forging device according to claim 5 comprises an alignment transcription attachment comprising: a thick-plate shaped block body that is set in contact with a surface of the punch holder on a side facing the stationary part, an extended bolt hole drilled in the block body to communicate with the reference stud hole of the punch holder, and the second group of adjusting bolts used in the alignment transcription operation and to be tightened from an outer side of the punch holder into a direction of the reference stud, wherein the alignment transcription attachment is coupled to the punch holder with the extended bolt hole communicating with the reference stud hole.
 7. An alignment transcription attachment to be coupled to a forging device, the forging device comprising: a stationary part comprising a die, a movable part reciprocally movable to and away from the stationary part in a moving direction, a punch holder detachably attached to the movable part, and a punch tool that is paired with the die and is detachably attached to the punch holder; the punch holder comprising: an upper reference stud hole drilled through the punch holder with an axis of the upper reference stud hole along the moving direction of the movable part, a lower reference stud hole drilled through the punch holder with an axis of the lower reference stud hole along the moving direction of the movable part in an opposing side of the upper reference stud hole across the punch tool, an upper reference stud fixed to the movable part such that the upper reference stud is loosely fitted in the upper reference stud hole of the punch holder, a lower reference stud fixed to the movable part such that the lower reference stud is loosely fitted in the lower reference stud hole of the punch holder, wherein either the upper reference stud or each of the upper and lower reference studs is defined as a reference stud, and either the upper reference stud hole or the lower reference stud hole in which the reference stud is loosely fitted is defined as a reference stud hole, a plurality of adjusting bolts each comprising a male screw portion, the adjusting bolts to be tightened with respect to the reference stud from an outside of the punch holder into a direction of the reference stud to move the punch holder into an alignment direction, defined as a direction in which the punch holder is moved to align the punch tool and the die, with fixing the punch holder at a position of the reference stud, and clamping nuts which are engaged with the upper reference stud and the lower reference stud, respectively, and fix the punch holder at a complete alignment position, defined as a position at which the punch tool and the die are aligned, the alignment transcription attachment comprising: a substantially thick-plate shaped block body that is set in contact with a surface of the punch holder at a portion covering the upper reference stud hole on a side facing the stationary part, an extended bolt hole drilled though the block body to communicate with the reference stud hole of the punch holder, an adjusting bolt tightened into a direction of the extended bolt hole from the outer side of the punch holder to be in contact with the reference stud, and a positioning nut movably engaged with the male screw portion of the adjusting bolt, wherein the block body is coupled or bolted to the punch holder with the extended bolt hole communicating with the reference stud hole, the adjusting bolt of the block body is tightened till the bolt hits the reference stud in alignment, the positioning nut is tightened till the positioning nut hits the block body, and the tightened positioning nut is un-rotatably fixed to the male screw portion of the adjusting bolt. 